#IP 1126 28 Mar - 3 Apr2016

International Women’s Day 2016: A day to Pledge for Parity

Every year, the 8th of March celebrates the success of women in different fields. The main focus of this day is to encourage and appreciate women. The day also aims to initiate more effective actions to safeguard the rights of women in the society. As all of us know, the day was originally called as International Working Women's Day. It began as a socialist political event and eventually blended into the cultures of different countries. In some places it simply became an occasion for people to express their respect and admiration for women.

International Women's Day (IWD) means different things to different people. For some it's a celebration, for others it's a call to for action to accelerate gender parity and for many, it's an opportunity to align and promote women in the society. Whatever be the objective, International Women's Day is the perfect moment for gender-focused action.

Consider the themes of the IWD during the last few years by the UN women:

Year 2013: “A promise is a promise: Time for action to end violence against women”

Year 2012: “Empower Rural Women - End Hunger and Poverty “

All said and done, have these celebrations actually brought any drastic changes over the years? Well in some fields women have excelled with exceptions, but not all are able to do so. Worldwide, women continue to contribute to social, economic, cultural and political achievement. But progress towards gender parity has slowed in many places.

The World Economic Forum predicted in 2015 that it would take until 2133 to achieve global gender parityie., to close the gender gap!! In the wake of the above we are now into IWD of 2016. The irony is that the theme for International Women’s Day 2016 is “Planet 50-50 by 2030: Step It Up for Gender Equality”. So how do you think IWD Day 2016 must be celebrated? Yes! By Pledging for Parity.

Everyone – men & women - can pledge to take a concrete step to help achieve gender parity more quickly - whether by helping women and girls achieve their ambitions, calling for gender-balanced leadership, respecting and valuing differences, developing more inclusive and flexible cultures or rooting out workplace bias. Each of us can be a leader within our own spheres of influence and commit to take pragmatic action to accelerate gender parity. Needless to say the need of the hour is --are you ready to accelerate gender parity?

Gender bias is western concept. India is the original home of the Mother Goddess. From times immemorial, women in India have always been honored and respected. The Article 14 of our Constitution accords equality for both genders. Mahatma Gandhi said, ‘Intellectually, mentally, and spiritually, woman is equivalent to a male and she can participate in every activity." From Sita in Ramayana to Kannagi in Silapathikaram to Rani Jhansi, these ladies are not only celebrated women but also their contribution to social change and awareness had been immense. Even Sri Ramakrishna Parmahamsa is said to have worshipped his wife, recognizing her divinity.

Only in India, Woman is worshipped as a personification of Shakthi [Strength], Saraswathi [Knowledge] and Lakshmi [Prosperity]. In Hindu Mythology, woman is said to have been given absolutely 50% of Mental, Spiritual and Physical space in the life of a man & Lord Shiva illustrated this in His Ardhanareeswara form.

Modern India is fortunate to have had many great women leaders –Nivedita, Vijayalakshmi Pandit Mother Teresa, Sarojini Naidu & then Indira Gandhi - only the second woman Prime Minster in the world. Women like Kalpana Chawla, Indira Nooyi , Kiran Mazumdar Shaw, Pratibha Patil and many more have excelled in their chosen fields & made India proud. In the arena of Science & Technology, Indian women have left an indelible mark. Kadambini (Basu) Ganguly was the first female physician of South Asia to be trained in western medicine. Janaki Ammal - Director-General of the Botanical Survey of India, Kamala Sohonie- the first female student of Prof C V Raman on plant physiology. Anna Mani a student of Prof CV Raman was also a Deputy Director General of the Indian Meteorological Department (IMD). Rajeshwari Chatterjee, the first woman engineer (electrical) from Karnataka, set up a microwave research laboratory at IISc. Darshan Ranganathan, an organic chemist was the Deputy Director at IICT, Hyderabad , Maharani Chakravorty a molecular biologist organized the first laboratory course on recombinant DNA techniques in Asia and the Far East and the list goes on & on…

The contribution of these stellar women leaders to the society as a whole and to women in particular is invaluable. Today, the Indian woman is emerging out of her conventional roles by realizing her inherent, unlimited potential and thus has begun to take up major challenges in all walks of life & has the indomitable spirit to succeed.

Women in Technology: While no one can argue that the number of women in technology is low – it’s definitely not zero. It is infact bubbling with amazing, creative, gutsy women who are either building technology or using it to build more things. We need to boost the voices of these women. They're all around the world, and working on amazing stuff - from rocket scientists, to humanitarian aid workers, to fashion designers & what not... So let’s keep shining a light on the diversity of women role models across the world.

Women have been creating amazing things in the world of computer science as well but often their contributions have gone unnoticed. Did you know that the first computer program was developed by women? yes they are Women of ENIAC… In 1946 six brilliant young women programmed the first all-electronic, programmable computer, the ENIAC, a project run by the U.S. Army in Philadelphia as part of a secret World War II project. Also do you know that a woman coined the term “debugging”? US born Grace Hopper and Howard Aiken designed Harvard’s Mark I computer, a five-tonne, room-sized machine in 1944. Hopper invented the compiler that translated written language into computer code and coined the terms “bug”and “debugging”when she had to remove moths from the device (for real!).

Likewise, there is Radia Perlman who has been called the ‘mother of the internet’. Yet it is unfortunate that for some women, fame just passed them by. History has not always been kind to women scientists. Sometimes the work was obscured by a famous mentor. Here are some notable female scientists who truly deserve greater notice:

Lise Meitner (1878-1968) for the discovery of nuclear fission; Otto Hahn, sole recipient of the Nobel Prize in chemistry in 1944. Emmy Noether (1882-1935), who devised a mathematical principle, called Noether's theorem, which became a foundation stone of quantum physics. Her calculations helped Einstein formulate his general theory of relativity. "It is really through her that I have become competent in the subject," he admitted. Rosalind Franklin (1920-1958) took X-ray photographs of crystallized DNA, in the early 1950s and proved that the molecule was a helix. But the Nobel Prize was awarded to James Watson and Francis Crick, who had used her data to elucidate the structure of DNA!

Yet on this International Women’s Day 2016, India’s national carrier airline, Air India, stands in history.

Hats off to the women Crew!! Celebrating the power of women, the flight AI 173 took the non-stop Delhi-San Francisco route setting a record for being the world’s longest all-women operated and supported flight. The flight that departed from New Delhi on March 6 at 0235 hrs has landed in San Francisco at 0600 hrs, having covered 17 long hours. They will be back home today.

This first-of-its-kind flight had an all-women staff, be it cabin crew, cockpit crew, check-in staff, doctor or customer care staff. Under the command of Captain Kshamta Bajpayee and Captain Shubhangi Singh, the flight’s First Officers are Captain Ramya Kirti Gupta and Captain Amrit Namdhari. Not just that, the ground staff - from operator to technician, engineer, flight dispatcher and trimmer - also all women. Now that’s some celebration for all of us, right?

In this background, this year’s IWD theme is apt in a way to consider taking the pledge for parity in whatever field women are contributing their might. Well, who knows the next Curie or Pasteur may be living /working right now on some part of our planet!!.

The signal propagation within the phased array system decides the radar cross section (RCS) of phased array. The reflection and transmission coefficients for a signal at different levels of the phased in scattering array system depend on the impedance mismatch and the design parameters. Moreover the mutual coupling effect in between the antenna elements is an important factor. A phased array system comprises of radiating elements followed by phase shifters, couplers, and terminating load impedance. These components pose respective impedance towards the incoming signal that travels through them before reaching receive port of the array system.

In this book, the RCS of a parallel-fed linear and planar dipole array is derived using an approximate method. The RCS is approximated in terms of array factor, neglecting the phase terms. The mutual coupling effect is taken into account. The dependence of the RCS pattern on the design parameters is analyzed. The approximate model is established as an efficient method for RCS estimation of phased arrays.

This book presents a detailed formulation of approximate method to determine RCS of phased arrays, which is explained using schematics, and illustrations. This book should help the reader to understand the impinging signal path and its reflections/transmissions within the phased array system.

Printed dipole antennas are known to be simple but more efficient than the wire antenna. The dielectric substrate and the presence of ground plane affect the antenna performance and the resonant frequency gets shifted. This bookincludes the electromagnetic (EM) design and performance analysis of printed dipole array on planar and cylindrical substrate. The antenna element is taken as half-wave centre-fed dipole. The substrate is taken as low-loss dielectric. The effect of substrate material, ground plane, and the curvature effect is discussed. Results are presented for both linear and planar dipole array. The performance of dipole array is analyzed in terms of input impedance, return loss, and radiation pattern for different configurations. The effect of curved platform (substrate and ground plane) on the radiation behavior of dipole array is analyzed.

This book presents a simple and systematic description of EM design of antenna array. It explains fundamentals of EM design and analysis of dipole antenna array through numerous illustrations. Thisbook focuses primarily on electromagnetic design and performance analysis to dipole antenna array on planar and cylindrical dielectric substrate. It is essentially a step-to-step guide for beginners in the field of antenna array design and engineering.

The concealment of aircraft from radar sources or stealth is achieved either through shaping, or radar absorbing coatings, or engineered materials, or plasma, etc. Plasma-based stealth is a radar cross section (RCS) reduction technique associated with the reflection and absorption of incident electromagnetic (EM) wave by the plasma layer surrounding the structure. Plasma cloud covering the aircraft may give rise to other signatures such as thermal, acoustic, infrared, or visual. Thus it is a matter of concern that the RCS reduction by plasma enhances its detectability due to other signatures. This needs a careful approach towards the plasma generation and its EM wave interaction.

Thisbook presents a comprehensive review of the plasma-based stealth, covering the basics, methods, parametric analysis, and challenges towards the realization of the idea. The book starts with the basics of EM wave interactions with plasma, briefly discuss the methods used to analyze the propagation characteristics of plasma, and its generation. It presents the parametric analysis of propagation behavior of plasma, and the challenges in the implementation of plasma-based stealth technology. This review serves as a starting point for the graduate and research students, scientists and engineers working in the area of low-observables and stealth technology.

The antenna radar cross section (RCS) depends on the field scattered by the antenna towards the receiver. It has two components, viz. structural RCS and antenna mode RCS. The latter component dominates over the former, especially if the antenna is mounted on a low observable platform. The reduction in the scattering due to the presence of antennas on the surface is one of the concerns towards stealth technology. In order to achieve this objective a detailed and accurate analysis of antenna mode scattering is required. In practical phased array, one cannot ignore the finite dimensions of antenna elements, coupling effect and the role of feed network while estimating the antenna RCS. This book presents the RCS estimation of an array with unequal-length dipoles. The signal reflections within the antenna system and the mutual coupling effect are considered to arrive at the total RCS for series and parallel feed. The scattering due to higher order reflections is neglected. The computations are valid for any arbitrary array configurations, including side-by-side arrangement, parallel-in-echelon etc.

This book presents a detailed and systematic analytical treatment of scattering by an arbitrary dipole array configuration with unequal-length dipoles, different inter-element spacing, load impedance. It includes several schematics, tables, and illustrations, and hence provides an adequate physical interpretation of the scattering phenomena within the phased array system.

In aerospace vehicle phased arrays are mostly of planar configuration. The radar cross section (RCS) of the vehicle is mainly due to its structure and the antennas mounted over it. There can be situation when the signatures due to antennas dominate over the structural RCS of the platform. This necessitates the study towards RCS reduction and control of antenna/ array RCS.

In this book, scattering of parallel-fed planar dipole arrays is determined in terms of reflection and transmission coefficients at different levels of the array system. The planar dipole array is considered as stacked linear dipole array along the y-direction. A systematic step-by-step approach is used to calculate RCS pattern including the finite dimensions of dipole antenna element. The mutual impedance between the dipole elements for planar configuration is determined. The scattering till second level of couplers in parallel feed network is taken into account. Phase shifters are modeled as delay line. All the couplers in the feed network are assumed to be four port devices.

It is shown that the array RCS can be reduced considerably towards low observable platform by an optimization of array design parameters, even in the presence of mutual coupling. This book presents a systematic step-by-step analytical formulation for RCS of planar half-wavelength centre-fed dipole arrays through various schematics and illustrations. The analytical description and analysis provided in this book should be useful for students, researchers, and design engineers of phased arrays.

In phased arrays, the generation of adapted pattern according to the signal scenario requires an efficient adaptive algorithm. The antenna array is expected to maintain sufficient gain towards each of the desired source and suppress the probing sources. This cancels the signal transmission towards each of the hostile probing sources leading to active cancellation.

In this book, a modified improved LMS algorithm is employed for weight adaptation of dipole array for the generation of beam pattern in multiple signal environments. The performance of dipole phased array is demonstrated in terms of fast convergence, output noise power and output signal-to-interference-and noise ratio. The mutual coupling effect and role of edge elements are taken into account. It is established that dipole array along with an efficient algorithm is able to maintain multilobebeamforming with accurate and deep nulls towards each probing source. This work has application towards active radar cross section (RCS) reduction.

This book consists of formulation, algorithm description and result discussion on active cancellation of hostile probing sources in phased antenna array. It includes numerous illustrations demonstrating the theme of the book for different signal environments, array configuration. The concept discussed in this book is simple to understand, even for the beginners in the field of phased arrays and adaptive array processing.

The radar cross section (RCS) of an object represents its electromagnetic scattering properties for a given incident wave. The analysis of scattered field is critical in military and defence arenas, especially while designing low observable platforms. It is well-known that the presence of an antenna/ array on the target influences its echo area significantly. The primary cause for such scattering of the incident signals is reflection that occurs within the antenna aperture and its feed network.

This book presents the detailed analytical formulation for the RCS of parallel-fed linear dipole array in the presence of mutual coupling. The RCS estimation is done based on the signal path within the antenna system. The scattered field is expressed in terms of array design parameters including the reflection and transmission coefficients. The computed results presented show the variation in the RCS pattern for the cases of with and without mutual coupling. The effect of finite dipole-length, inter-element spacing, scan angle, array configuration, amplitude distribution and terminating load impedance on the RCS pattern is studied. It is shown that the array RCS can be controlled by choosing optimum design parameters, including terminating impedance and geometric configuration. This book explains each step of the RCS estimation and analysis of dipole array with detailed schematics, tables and illustrations. Moreover it includes parametric analysis of RCS estimation and control. This book provide an insight into the physics of scattering within the phased array system.

The High Impedance Surface (HIS) is a preferred substrate for low profile antenna design, owing to its unique boundary conditions. Such substrates permit radiating elements to be printed on them, without any disturbance in the radiation characteristics. Moreover HIS provides improved impedance matching, enhanced bandwidth, and increased broadside directivity owing to total reflection from the reactive surface and high input impedance.

This book presents electromagnetic (EM) design and analysis of dipole antenna array over high impedance substrate. Different configurations of HIS are considered for the array design on planar and non-planar high-impedance surface. Results are presented for cylindrical dipole, printed dipole, and folded dipole over single and double layered square-patch based-HIS and dogbone-based HIS. The performance of antenna array is analyzed in terms of performance parameters such as return loss and radiation pattern. The design presented shows acceptable return loss and mainlobe gain of radiation pattern. This book provides an insight to EM design and analysis of conformal arrays. This book is a comprehensive text for beginners in the design and analysis of HIS-based antenna array. It includes pictorial description of both planar and non-planar array design and the detailed discussion of the performance analysis of HIS-based planar and non-planar antenna array.

#IP 1125 14 - 20 Mar 2016

Congratulations!!!

"NAL-ARES consortium has received the first order from Jyoti Nivas College, a private autonomous Educational Institution in Bengaluru for the 900 W NALWIN Wind Turbine System. NALWIN will work in conjunction with the grid tied Solar PV system."

#IP 1124 7 - 13 Mar 2016

Best paper presentation

M Sendil Murugan, Technical Officer at CSMST, received an award for best paper presentation in the Second Indo – Canadian Symposium on Nano-Science and Technology (ICSNST-2016) held at National Institute of Engineers (NIE), Mysuru during February 18-19, 2016.